Generally, a cyclone dust separating apparatus, also known as a cyclone dust collecting apparatus, draws in contaminant-laden air from a surface by negative air pressure generated by a vacuum source in a vacuum cleaner body. As air flows through a cyclone dust collecting apparatus, the air generates a rotating or cyclonic air stream or vortex in the cyclone dust separating apparatus that causes suspended dirt particles to be centrifugally separated from the air.
FIG. 1 is a schematic view of cyclone dust collecting apparatus for a vacuum cleaner. Reference numerals 1, 2 denote a cyclone dust collecting apparatus and a cleaner body, respectively. Reference numerals 10, 20 and 30 denote a cyclone body, a contaminants-collecting receptacle and a grill, respectively.
As shown in FIG. 1, the cyclone body 10 comprises an air intake port, also referred to herein as an inflow port 11 and an air outlet or exhaust port, referred to herein as an air outflow port 12. The air inflow port 11 is connected with an air path or duct 3 that is fluidly communicated with an inlet of a suction brush (not shown) of the cleaner body 2 when the cyclone dust collecting apparatus 1 is mounted to the cleaner body 2. The air outflow port 12 is connected with an air discharging port (not shown) at an upside of the cyclone body 10. The air outflow port 12 is connected with an air discharging path fluidly communicated with a motor-driven vacuum source in a motor chamber 5 in the cleaner body 2.
Dust and contaminant-laden air flowing into a vacuum cleaner via the suction brush streams into the cyclone body 10 through the air inflow path 3 and the air inflow port 11 of the cleaner body 2, tangentially to the cyclone body wall. Because the air flows in tangentially, a rotating stream, which is also known as a cyclone or vortex, is generated in the cyclone body 10. Dust and contaminants are separated from the rotating stream by a centrifugal force, cleaned air is discharged to the outside through the air outflow port 12, and an air discharge path 4 and the motor driving chamber 5 of the cleaner body 2.
The contaminant collection receptacle 20 is detachably engaged with a bottom portion of the cyclone body 10 and collects dust and contaminants centrifugally separated from air by a rotating stream in the cyclone body 10.
A grill 30 is mounted at an entrance of the air outflow port 12 in the cyclone body 10 to prevent the separated dust and contaminants from counterflow to the cleaner body 10 through the air outlet port 12. The grill 30 comprises a grill body 31, a plurality of paths 32 arranged around the outer circumference of the grill body 31 to fluidly communicate with the air outflow port 12 and a counterflow prevention port 33, a function of which is to prevent collected contaminants from counterflowing and escaping the cyclone dust collecting apparatus 10.
The efficiency of a cyclone dust collecting apparatus depends in part on the distance d between the counterflow prevention part 33 and the cyclone body 10. That is, if an end of the counterflow prevention part 33 is arranged to be close to an inner circumference of the cyclone dust collecting apparatus, filtering effectiveness can be improved because it can prevent contaminants collected in the contaminants collection receptacle 20 from counterflow. However, large contaminants are sometimes trapped or caught such that they may obstruct generation of rotating stream or block the air discharge path.
On the other hand, if the counterflow prevention part 33 is arranged too far from the inner circumference of the cyclone body 10, large contaminants can be easily collected in the contaminants collection receptacle 20, however, large contaminants collected in the contaminants collection receptacle 20 may be affected by the rotating stream in the cyclone body 10 such that they counterflow from a bottom surface of the contaminants collection receptacle 20 and are trapped or caught by the grill 30, and as a result, dirt collection of the cyclone dust collecting apparatus 1 may decrease.